Guiding long flexible bodies



Aug. 23, 1938. w LEA 2,127,606

GUIDING LONG FLEXIBLE BODIES Filed Jan. 7, 1957 INVENTOR I V/W/OW? Georye Lea ATTORNEYS Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE 2,127,606 GUIDING LONG FLEXIBLE nonms' Application January '7, 1937, Serial No. 119,389

1 Claim.

This invention relates to rayon manufacture,

and is concerned primarily with maintaining uniform tension on rayon strand as it passes from a spinnerette to a spool on which it is 5 wound.

In the manufacture of rayon by the bobbin process, a viscous dispersion of a cellulose derivative or other suitable compound is extruded from a spinnerette into a coagulating or setting ll-medium, whence it passes to a revolving spool on which it is cross-wound. In its travel the strand passes through a guide, which is mounted upon a traverse, and it is thereby caused to reciprocate in a plane parallel to the axis of the Brotating spool. In modern practice, it is customary to cross-wind the freshly spun rayon by the "quick-traverse method, which means that the reciprocating motion is comparatively rapid with respect to the number of revolutions made -by the spool in unit time, the object being to produce an open wind, characterized by interstices which facilitate the passage of vliquids through the yarn cake during subsequent wet processing steps.

35 Several kinds of traverse motion are known. Amongst theseis the type conventionally known as the oscillating' pendulumh It is this type with which my invention is particularly concerned although it be evident to those skilled in the art that the principle of my invention is equally applicable ineonnection with the type of traverseknown as the ,'horizontal traverse".

In the pendulum-type the thread guide is amxed at or near'the end of the pendulum arm,

which is suspended from a rocking shaft, and by virtue of the oscillatory motion, it describes an arc of a circle. As the traverse guide moves back and forth, the distance between it and the spinnerette constantly changes, being at a maximum when the guide is swung to. a position opposite the ends of the spool, and at a minimum when in its passage it occupies a position midway between these extremes.

Freshly spun rayon is still substantially plastic at the instant that it reaches the traverse guide, because it is not practical in modern rayon manufacture to attempt to provide conditions whereby the filaments are completely solidified during the brief moment of their passage from spinnerette to bobbin. A constantly changing tension or strain is exerted on the strand, which is reflected in a periodic andunequal deformation throughout its length. This is eventually manifested in the finished yarn by a corresponding l'unction with variability in its abilityto take up certain dyestuffs.

As a result of my investigations, I have discovered that uneven strain in cross-winding with the aforementioned resultant defects in the 5 wound product may be largely eliminated if the distance between the reciprocating or traverse guide and the spinnerette is kept substantially constant during the traverse stroke, and I have developed an improved apparatus in which this constant relationship is maintained.

In accordance with my invention, the distance between the rocking shaft and the traverse guide is caused to change as the pendulum is swung back and forth, instead of causing the distance between the spinnerette and traverse guide to change as is true of existing pendulum traverse motions. This is done by placing the traverse guide on an extension of the pendulum, the ex: tension being slidable along the pendulum on a line substantially perpendicular to the major axis of the rocking shaft. The extension of the pendulum is provided with a rider which is adapted to slide in a track lying transversely to the extension and parallel to the plane which the pendulum describes while swinging. The track should be so curved that the rate at which the pendulum extension slides on the pendulum when the latter is swung back and forth is such as to keep substantially constant the distance between the traverse and the stationary guide.

My invention is also applicable to that type of traverse mechanism in which the pendulum is replaced by an arm which does not swing but instead is oscillated uniformly throughout its length.

'These and otheraspects 'of my invention will be more thoroughly understood in the light of the following detailed description taken in con 40 the accompanying drawing, in

which Fig. 1 is a, diagrammatic sectional front elevation of a presently preferred form of the apparatus of my invention, and 5 Fig. 2 is a diagrammatic sectional side eleva- 4 tion of the apparatus of Fig. 1. I

Referring to the drawing it will be seen that a conventional type of bobbin I is rotatably mounted on a base 2 by means of a'concentrically 5o 5 (or a spinnerette, not shown) is mounted at a considerable distance from the bobbin in an imaginary plane passing perpendicular to the K longitudinal axis of the bobbin and the spindle at about the center of the bobbin.

A traverse guide 6 such as a ring is disposed adjacent the bobbin and is adapted to reciprocate in a second imaginary plane substantially parallel to the longitudinal axis of the bobbin, said plane passing through the stationary guide.

A rocking shaft 8, such as a pipe, is disposed on the side of the bobbin opposite to the stationary guide and spaced at a considerable distance from the bobbin. The rocking shaft lies with its longitudinal axis in the aforementioned second plane and at right angles to the longitudinal axis of the .bobbin. Conventionalmeans (not shown) are provided for rocking the shaft through a relatively small angle, the size of which is determined by the length of the bobbin and the distance from the bobbin to the rocking shaft.

Fastened around the rocking shaft by a pair of bolts 9, I0 is a split collar II. The collar half I! nearer to the bobbin is provided with a cylindrical boss l3 formed integrally therewith and provided with a concentric hole into which is fitted rigidly the end of a pendulum l4. One end of the pendulum is held in the boss by a pin l5 passing through the pendulum and the wall of the boss. The oppos'ite end of the pendulum is formed integrally as a cylindrical rod 14a which fits slidably into a cylindrical cavity running lengthwise in an end of 5- that the extension and the pendulum will not rotate with respect to each other, but are free to slide one within the other.

About midway on the extension and on each side are respectively rotatably mounted two riders l8, l9 by means of a pin 20 passing through the extension and the approximate centers of the riders. These riders are shaped like short segments cut from a ring of rectangular cross section and are free to turn on the pin. A cylindrical pin mounted rider may also be used.

Each rider is mounted respectively in tracks 2|, 22 each comprising a pair of arc-shaped rails 2 l A, ZIB, ,22A, 223, which are curved to flt the slider. The tracks in turn are fastened to the face of rigid arms 23, 24 mounted on the base.

The tracks extend in a plane parallel to the axis of the bobbin and parallel to the plane of swing of the pendulum. They are curved about a point lying on an imaginary line (drawn from the center of the rocking shaft cross-section to the stationary guide) between the tracks and the stationary guide. The radii of curvature of the tracks are such that, as the pendulum is swung back and forth by the rocking shaft the end of the pendulum extension carrying the traverse describes a circular are having its center at the stationary guide.

In the operation of the mechanism illustrated, freshly spun yarn 25 is passed through the stationary guide and then through the reciprocating traverse guide to be wound on the rotating bobbin. Force is simultaneously applied to rock the rocking shaft through an angle such that the traversestroke is equal to that portion of the length of the bobbin on which it is desired to build up A stationary aperture which may be ring guide the yarn. Kit is desired to form a yarn cake having bevelled ends the angle through which the shaft is rocked is progressively decreased during the winding of a cake, by any of the several known mechanisms for effecting this result.

As the pendulum is swung back and forth its effective length, i. e. the distance from the center of the rocking shaft cross-section to the traverse is changed in periodic progression. At the outer termination of each stroke the effective length of the pendulum is greater than at the center of each stroke because the sliders riding in the tracks pull the extension and cause it to slide upon the pendulum. In other words, as the pendulum is swung back and forth, the pendulum reciprocates in the cavity in the extension of the pendulum. The are through which the traverse reciprocates is, therefore, dependent upon the curvature of the tracks.

In the case illustrated the arc described by the traverse is a circular one having its center at'the ring guide, for the reason that in such case the yarn between stationary guide and traverse is subjected to uniform tension. If, however, for any reason it should be desired to move the traverse through an arc of any other shape or radii o'r curvature in accordance with well-known geometrical principles.

The invention has been described in detail as applied to a pendulum type of traverse mechanism. However, it is equally applicable to the type of mechanism in which the pendulum is reciprocated transversely to its length instead of being swung, as will be immediately apparent.

Thus the apparatus of Figs. 1 and 2 may be arranged so that the rocking shaft 8 is not rocked but instead is reciprocated transversely to its major axis in a plane perpendicular to the pendulum. This may be accomplished by a number of known mechanisms (not shown) employed in the textile industry.

Inasmuch as the pendulum I4 is clamped to the shaft which is reciprocated laterally instead of being rocked, the pendulum is reciprocated as distinguished from being swung. However, the lateral reciprocation will result in changing the distance between the movable guide 6 and the stationary guide 5 unless some'means are provided for changing the combined effective length of the members I4, A. This is accomplished by the same means as in the pendulum type of traverse mechanism described herebeiore, except that the curvature of the slider and the tracks is changed.

I claim:

In apparatus for guiding an elongated plastic flexible body of uniform cross section having a.

pair of neighboring guides through which said body is passed in a relatively taut condition, one of said guides being stationary and means being provided for reciprocating the other guide transversely to the direction of passage of the body, the improvement which comprises means for maintaining substantially comtant the distance between said guides during reciprocation of the reciprocable guide, said means including an elongated arm oscillatable in a direction transverse to its major axis and to the direction of passage of said body, an elongated extension mounted slidably on said arm and bearing the reciprocable guide, a track disposed in a direction transverse to the major axis of the arm and to the direction of passage of the body, and a rider slidably mounted on said track and. attached to the extension, .the curvature of the track being such that the extension periodically slides longitudinally on the arm during oscillation of the latter, thus changing the effective combined length of the arm and the extension periodically WILLIAM GEORGE LEA. 

